<!DOCTYPE html>
<html>
<head>
  <style>div { background:yellow; }</style>
  <script src="http://code.jquery.com/jquery-latest.js"></script>
</head>
<body>
  <div><p>Free me...</p><span>...and me</span></div>
  <div><p>Me too!</p></div>
<script>$("p").unwrap();</script>

</body>
</html>